Determining physical memory installed

Step 4. Under System (Computer for Windows XP) will be listed the amount of RAM currently installed and detected.

To determine the amount of available system resources including memory as well as what is currently being utilized open the Task Manager. To quickly get to the Task Manager press CTRL + ALT + DEL and click the Task Manager button. In the Processes tab you will be able to see which programs are using what resources. In the Performance tab you will have an overall picture of all the system resources.